Principal Investigator: Professor Mark Woodward

We have recently completed meta-analyses involving millions of
subjects, which showed that, although smoking increased risk
considerably in both sexes, women who smoke have a 25% greater
excess relative risk for coronary heart disease compared to men who
smoke. Although not as strong, there is also a trend towards a similar
excess risk for stroke among women smokers compared with men.
Furthermore, we have published other data, which suggest an excess
relative risk of around 100% from smoking for women, compared to
men, for lung cancer mortality. One possible reason for these excess
relative risks in women is that their smoking habits tend to be more riskinducing.
For example, they may smoke more, or start at a younger age.
On the other hand, it may be that women have less risk-inducing
smoking habits, in which case the excess relative risks we, and others,
have found are even more remarkable, with implications for targeted
public health measures to prevent smoking and promote quitting.
We request the use of the baseline UK Biobank data on smoking habits
to make comparisons between women and men, so as to understand
whether variations in habits may explain the excess relative risks we
have found. We shall also explore whether sex differences persist within
important subgroups of the UK Biobank population, by age, selfreported
illness, socio-demographic status, and ethnicity. These will all
be cross-sectional analyses; in the future we propose to make a further
application to investigate whether sex-specific smoking habits contribute
to the risk of the major smoking-related chronic diseases using
longitudinal UK Biobank data.